Describes experiments intended to produce a better understanding of the holographic method of producing images and optical imaging by other optical systems. Application of holography to teaching physics courses is considered. (Author/SA)

Describes and explains some aspects of the motion of a top, the extreme end of which is made round, spinning on surfaces provided with friction. (Author/GA)

A discussion of Edwin Land's experiments with color images from black-and-white photographs. Information is presented for duplication of these experiments by the amateur photographer. (BB)

An activity is described that is designed to give students a chance to learn about speed by calculating their own running or walking speed and the speed of cars. (MP)

Discusses the determination of the position of the absorption maximum in wide bands as well as the confidence limits for such calculations. A simple method, suited for pocket calculators, for the numerical evaluation of these calculations is presented. (BB)

Discusses advantages of radial diffusion assay in determining presence of enzyme and/or rough approximation of amount of enzyme activities. Procedures are included for the preparation of starch-agar plates, and the application and determination of enzyme. Techniques using plant materials (homogenates, tissues, ungerminated embryos, and seedlings)…

Presents the views of the chairman of the group of scientists that prepared the preliminary proposal on DNA guidelines for the 1975 Asilomar Conference. Examples and illustrations are used to argue that stronger and tighter controls than those outlined in the National Institutes of Health (NIH) guidelines are needed. (CS)

Explores three classic turning points in science and presents close-up views of the scientists involved and their discoveries. Discussions include William Herschel and light; Lavoisier, Priestley, Scheele and oxygen; and Faraday and electromagnetism. Presents suggestions for experiments to demonstrate these discoveries. (JRH)

Considers the nature and extent of bias toward experimentation and against correlational studies. Argues for the use of correlational studies and describes a field-tested approach to enabling students to direct open-ended investigations of this type. (45 references) (JRH)

Describes an approach to incorporating cooperative learning into the anatomy laboratory without diminishing the quality of instruction of the subject matter. Discusses the background, organization of groups and group tasks, evaluation of the approach, and potential disadvantages of cooperative learning. Contains 11 references. (JRH)

Describes experiments that illustrate a number of general principles such as pattern identification, displacement chromatography, and salting-out adsorption, plus an experiment that demonstrates that identification by chromatography alone is impossible. Illustrates that chromatography is still possible with quite simple means, notwithstanding the…

Presents activities that can be used to introduce thin-layer chromatography at the undergraduate level in relatively less developed countries and that can be performed with very simple and commonly available apparati in high schools and colleges. Activities include thin-layer chromatography with a test-tube, capillary feeder, burette, and rotating…

Describes a low-cost four-color LED photometer developed to overcome the rising cost of laboratory equipment used in general chemistry labs and introduce instrumentation at the undergraduate level. The photometer detects absorbance at selected wavelengths of visible light but retains the advantages of a dual-beam system. The unit is compact and…

Presents an interview protocol used to identify and evaluate students' conceptions of plants which is an invitation to participate in the third national study exploring elementary students' science conceptions. (YDS)

Describes an experiment to demonstrate a simple method for measuring fungus growth by monitoring the effect of temperature on the growth of Trichoderma viride. Among the advantages that this experimental model provides is introducing students to the importance of using the computer as a scientific tool for analyzing and presenting data. (AIM)